Neural control of skeletal muscle cholinesterase: a study using organ‐cultured rat muscle.

Davey, B. L. K.; Younkin, L.H.; Younkin, Samuel G.

doi:10.1113/jphysiol.1979.sp012749

Cited by 40 publications

(12 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The increase in AcCho esterase in extract-treated cultures is consistent with earlier reports that neural extracts slow the loss of AcCho esterase in denervated muscle (36)(37)(38). AcCho receptors cluster at newly formed synapses in the absence of synaptic function and muscle activity (7,13), but some degree of muscle activity is required for the accumulation of AcCho esterase at sites of transmitter release (13).…”

Section: Discussionsupporting

confidence: 89%

See 1 more Smart Citation

Induction of acetylcholine receptors on cultured skeletal muscle by a factor extracted from brain and spinal cord.

Jessell¹,

Siegel²,

Fischbach³

1979

Proc. Natl. Acad. Sci. U.S.A.

203

100

View full text Add to dashboard Cite

Extracts of chicken brain and spinal cord increase the total number of acetylcholine receptors and the number of receptor clusters on uninnervated skeletal myotubes in culture. The active component in these extracts may be unique to neural tissue. Spinal cord cells grown in culture contain the active factor and they secrete it into the medium. Most of the activity is associated with a small molecule, possibly a peptide. Such a factor may be responsible for the clustering of receptors at newly formed nerve-muscle synapses.Acetylcholine receptors (AcChoRs) are distributed over the entire surface of embryonic skeletal myotubes (1-3). Soon after embryonic spinal cord neurites contact myotubes in vitro, synapses form and clusters of AcChoRs can be identified at sites of transmitter release (4, 5). AcChoR clusters are present on uninnervated myotubes in vitro, but it is now clear that newly arrived nerve processes induce new AcChoR clusters rather than seek out preexisting ones (4-7). In adult muscle, the density of extrajunctional receptors is 3-4 orders of magnitude lower than in the synaptic membrane (8, 9), so extrasynaptic receptors must disappear soon after innervation. Both the initial clustering of AcChoRs and the subsequent dramatic decrease in the number of extrajunctional receptors have been extensively studied.Muscle activity is an important determinant of extrajunctional acetylcholine (AcCho) sensitivity in adult and embryonic skeletal muscle (10-12). In-contrast, activity does not influence the clustering of AChoRs at synapses. New clusters appear at nerve-muscle contacts in vitro when cultures are grown in the presence of a-bungarotoxin (aBTX), curare, or tetrodotoxin (7, 13). This finding has renewed interest in the possibility that a chemical factor released from motor nerves may influence the number of AcChoRs.Some evidence for such a factor has already been obtained. In chicken spinal cord explant/muscle cocultures, AcCho sensitivity and the density of 125I-labeled aBTX binding sites on myotubes close to the explant are greater than on myotubes located farther away in the same culture (14). This may reflect the diffusion of a soluble factor from the spinal cord tissue. Rat brain and spinal cord extracts increase AcChoR numbers on L6 myotubes to levels found on primary rat myotubes and also promote the appearance of AcChoR clusters (15). Media conditioned by a hybrid neuroblastoma cell line increase the number of AcChoR clusters but not the total number of receptors on primary mouse myotubes (16).In this paper we document physiological effects of chicken brain and spinal cord extracts on primary chicken myotubes and describe the partial purification of a factor that increases the number and induces the clustering of AcChoRs.The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U. S. C. §1734 solely to indicate this fact. 5397MATERIALS AND METHODS Cell Culture. Muscle cultures were ...

show abstract

Section: Discussionsupporting

confidence: 89%

“…It remains to be determined if the release is restricted to synaptic nerve-muscle contacts. Protein is released along with AcCho from stimulated adult motor nerve terminals (35), and recent experiments have demonstrated that stimulated motor axons release a substance that maintains AcCho esterase at denervated end plates (36).…”

Section: Discussionmentioning

confidence: 99%

Induction of acetylcholine receptors on cultured skeletal muscle by a factor extracted from brain and spinal cord.

Jessell¹,

Siegel²,

Fischbach³

1979

Proc. Natl. Acad. Sci. U.S.A.

203

100

View full text Add to dashboard Cite

show abstract

“…Both endplate and nonendplate AChE decrease dramatically after denervation (Guth et al, 1964(Guth et al, , 1967Drachman, 1972;Hall, 1973;Davey and Younkin, 1978;Collins and Younkin, 1982), and both recover when reinnervation occurs at either the original or an ectopic site (Guth and Brown, 1965;Vigny et al 1976;Weinberg and Hall, 1979). The available evidence suggests that the influence of innervation on nonendplate AChE is mediated by the activity (electrical and/or mechanical) set up in muscle by nerve and that the influence of innervation on endplate AChE (the asymmetric forms in particular) is mediated in part by activity and in part by another mechanism (Drachman, 1972;Davey and Younkin, 1978;Davey et al, 1979;Fernandez et al, 1979Fernandez et al, , 1980Rubin et al, 1980;Lomo and Slater, 1980;Ranish et al, 1980). Cultured embryonic rat myotubes appear to be excellent cells for studying the effect of electromechanical activity on AChE and on the asymmetric forms of AChE in particular.…”

Section: Discussionmentioning

confidence: 99%

Cellular localization of the molecular forms of acetylcholinesterase in cultured embryonic rat myotubes

1982

View full text Add to dashboard Cite

Three different methods were used to quantitate the external and intracellular acetylcholinesterase (AChE) in cultured embryonic rat myotubes. The results from these methods were in excellent agreement and showed that one-fourth of the AChE is external and three-fourths is intracellular in these cells. The molecular forms of AChE in the intracellular and external compartments then were analyzed. To isolate intracellular AChE, external AChE was inactivated irreversibly by treating myotubes at 2°C with 10 PM methanesulfonyl fluoride and 100 PM decamethonium for 1 hr. To isolate external AChE, myotubes at 2°C were first exposed to 1.0 PM echothiophate for 15 min to protect (diethylphosphorylate) external AChE and then treated with 1.0 mM methanesulfonyl fluoride for 30 min at 37°C to inactivate intracellular AChE irreversibly. Control myotubes and myotubes in which the external or intracellular enzyme had been isolated were extracted sequentially to separate globular, asymmetric, and nonextractable AChE. Individual globular and asymmetric forms then were analyzed by velocity sedimentation on sucrose gradients. The fractions in which external enzyme had been isolated as diethylphosphorylated AChE were reactivated with l-methyl-2-hydroxyiminomethylpyridinium prior to analysis. Our data indicate that intracellular and external AChE have different compositions. Intracellular AChE is 79% globular forms (20% 10 S and 59% 4 S), 17% asymmetric forms (6% 16 S, 5% 12.5 S, and 7% other), and 4% nonextractable enzyme. External AChE is 55% globular forms (26% 10 S and 29% 4 S), 32% asymmetric forms (12% 16 S, 10% 12.5 S, and 10% other), and 13% nonextractable enzyme; therefore external enzyme is composed of relatively more 10 S, 16 S, 12.5 S, and nonextractable AChE and relatively less 4 S AChE. The most striking finding to emerge from this study is that the globular and asymmetric forms are all predominantly intracellular in cultured embryonic rat myotubes. Our results indicate that 85% of the 4 S, 69% of the 10 S, 59% of the 16 S, and 56% of the 12.5 S forms are intracellular. These results support the hypothesis that the 10 S and asymmetric forms of AChE are assembled intracellularly from 4 S precursors.The enzyme acetylcholinesterase (AChE) occurs in a isolated from the electric organ of the eel Electrophorus number of molecular forms. Three of these forms are electricus. The three asymmetric forms are designated globular proteins and three are asymmetric. The globular Ad, As, and Alz and consist of one, two, forms are monomers, dimers, and tetramers of the basic or three tetrameric assemblies of identical catalytic subcatalytic subunit designated G1, Gz, and Gd (Bon et al., units attached to an elongated collagen-like tail Vigny et al., 1979). The structure of the asymmetric al. Rosenberry and Richardson, 1977; Anglister forms has been analyzed most carefully using AChE and Silman, 1978).

show abstract

“…A number of studies have appeared on the effects of extracts of CNS or peripheral nerves on the maintenance of AcChoEase in preparations of cultured vertebrate skeletal muscle in vitro (4)(5)(6)(7)(8)(9). In most of these reports, it was concluded that the active principle is a heat-labile protein of relatively high molecular weight.…”

Section: Neurobiology: Koelle Et Almentioning

confidence: 99%

Partial characterization of the neurotrophic factor for maintenance of acetylcholinesterase and butyrylcholinesterase in the preganglionically denervated superior cervical ganglion of the cat in vivo.

Koelle¹,

Sanville²,

Rickard³

et al. 1984

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

In continuation of previous reports, it was found that the neurotrophic factor (NF) of the central nervous system of the cat for the maintenance of acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7; AcChoEase) in the denervated cat superior cervical ganglion is a heat-stable compound of low molecular weight (<1,000) and that it is probably a peptide. Acetylcholine and nerve growth factor were eliminated as the NF; cyclic AMP produced an effect similar to that of the NF. The NF is probably not present in significant amounts in liver or skeletal muscle; it appears to be present in small intestine. It does not modify the AcChoEase content of the nondenervated cat superior cervical ganglion. Possible mechanisms of action of the NF are discussed.We have shown that arterial infusion for 24 hr of an extract of the brain, spinal cord, and sciatic nerves of cats prevents almost completely the fall in the acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7; AcChoEase) and butyrylcholinesterase (acylcholine acylhydrolase, EC 3.1.1.8; BtChoEase) contents of the cat superior cervical ganglion (SCG) that otherwise results 48 hr after preganglionic denervation (1). It was shown subsequently that ligation of the external carotid (EC) and lingual (L) arteries is necessary to obtain the full effect of the extract and to counteract partially a similar but lesser effect produced by continual anesthesia with sodium pentobarbital; although the effect was demonstrable when the infusion time was reduced to 6 hr, it was much less marked and consistent than with 24-hr infusion (2). The compound(s) responsible for the preservation of ganglionic AcChoEase and BtChoEase was designated a neurotrophic factor (NF).The present report describes studies addressed to characterization of the NF by 24-hr infusions of authentic agents and of dialyzed and enzyme-treated preparations of the central nervous system (CNS)/sciatic nerve extract. METHODSPreparation of the infusion extract (extract of the brain, spinal cord, and sciatic nerves of cats), anesthetic and surgical procedures, and methods for homogenization of ganglia, for determination of ganglionic AcChoEase, BtChoEase, and protein contents, and for calculation of statistical significance of mean differences were identical with those reported previously (1). Under sodium pentobarbital anesthesia (35 mg/kg of body weight i.p.), 1 cm was resected from both cervical sympathetic trunks; the wound was sutured, and Combiotic (penicillin and dihydrostreptomycin, Pfizer; 0.5 ml) was given i.m. The following day cats were anesthetized as before and treated with atropine (1.0 mg/kg i.p.); artificial respiration was administered through a tracheal catheter attached to a Palmer pump, and a slow i.v. infusion of 5% glucose/0.45% NaCl was started. Heparin at 50 units/kg was given i.v. just prior to bilateral ligation of the EC and L arteries and was repeated every 6 hr. Infusion of the solution under test was begun -24 hr after denervation and continued until the time of sac...

show abstract

Neural control of skeletal muscle cholinesterase: a study using organ‐cultured rat muscle.

Cited by 40 publications

References 23 publications

Induction of acetylcholine receptors on cultured skeletal muscle by a factor extracted from brain and spinal cord.

Induction of acetylcholine receptors on cultured skeletal muscle by a factor extracted from brain and spinal cord.

Cellular localization of the molecular forms of acetylcholinesterase in cultured embryonic rat myotubes

Partial characterization of the neurotrophic factor for maintenance of acetylcholinesterase and butyrylcholinesterase in the preganglionically denervated superior cervical ganglion of the cat in vivo.

Contact Info

Product

Resources

About